My goodness! Both hands must be blistered by now with touching that hot stove. I know it is very difficult to let go, i.e., drop the rope, but you have to do it. You do realize that the more you communicate w/him and ask questions, the more your mind is going to be working overtime and you are giving him entirely too much space in your head. I want to ask you a question...how long to you sit and analyze his every word/action after you've been around him or heard from him?
KC, you are now on thread 17...it's time to drop that rope and start focusing on your son's party and on YOU! No one is any more important than your son at this time. Your expectations of your son's father and your h have to be zero at all times for now. If his father shows up, that's fine, if your h shows up, that's fine...but you are the more important person in your son's life and he needs his mother to focus on him and his special day.
As for your h, leave him be. The more you touch that hot stove, the more you are going to spin and twirl in the wind. You are the only one that can stop the twirling. Also, I think it's time that you put those self help books away for a bit and focus on the here and now and get out there and enjoy your life for now. Books are great, but human interactions are far better for the self esteem. Go for a drive, stop by a cafe and have a cup of coffee or see what is open and take a walk into a business and just browse. Nothing says you have to purchase anything...turn your focus on to something other than your h.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.